Scuba

Every diver has a different SAC rate (Surface Air Consumption rate). We all breathe in different amounts of air, and have different breathing rates. It also depends on how deep you're talking. Remember, for every 30-33 feet down you go, the pressure reduces the volume in half.

Answer you're probably looking for:

an aluminum 80 cubic foot tank, at about 30 to 50 feet will last me 45 to 60 minutes.

I just noticed the other question at the bottom of this:

The effect of increased water depth on a scuba diver?

Now here's the fun question to answer. Breathing compressed air at depth can be DANGEROUS. Let's say you take a breath of air at 30 feet, and then hold your breath while you come up to the surface (NEVER DO THIS!). The volume of the air in your lungs would double. Odds are your lungs can not hold this much volume, and you can cause your lungs to explode (collapse)

Another effect of breathing air at depth is called "Nitrogen Narcosis". Air is basically 21% oxygen, 79% nitrogen. At the surface ... not a problem. BUT if you're breathing air at depth, the Nitrogen starts messing with you a bit.

The first way is Nitrogen Narcosis. It affects your ability to think. The best way I've ever heard this described is the "Martini Effect". For every 30 feet down you go, it's like having a vodka martini on an empty stomach. So if you're at 120 feet, it's like 4 martinis on an empty stomach. Kinda tipsy.

Now, for the DANGEROUS aspect of Nitrogen at depth. Your lungs take air, and put it into your blood stream. Again, at the surface, this is not a problem. And when you're at depth this isn't necessarily a problem. Where you run into a problem is surfacing. If you come up too fast, or miss your decompression stops which allow you to offgas the nitrogen, nitrogen can form bubbles in your blood stream. The severity of this ranges depending on how deep you are, and how long you were at depth. Scuba divers have computers and dive tables to figure these things out. If you have the nitrogen bubbles forming in your blood stream, it's called "Decompression Illness" or more commonly "The Benz". Treatment can be a range from doing nothing and letting your body to naturally offgas, to having to go into a decompression chamber which puts you back into pressure as if you were at depth and then bring you back slowly. This is of course assuming you survive to get to a hospital with a chamber. Some divers die before they hit the surface. The worst case I've heard of was where they attempted to draw blood from a diver, and the blood had so many bubbles in it ... it was a FOAM. (That diver lost his life before reaching the hospital).

The average adult at rest inhales and exhales something like 7 or 8 liters (about one-fourth of a cubic foot) of air per minute. That totals something like 11,000 liters of air (388 cubic feet) in a day.

because they found better and safer jobs.

Really as long as you want. You can store it at lower than 100 PSI for a long time, and you can store it in your basement. I really wouldn't store it with the cap off, but somehow you would need to mark it if you know it is almost at 100 PSI, because even the best divers cannot dive with 100 PSI safely. I wouldn't store it at full pressure, especially on a really hot day.

They can hear more, but not better.

Because of the density of water, vibrations are changed in pitch, and may be muffled and garbled. Since clarity is the most important factor in hearing, underwater communication is mostly done by hand signals instead.

On the other hand, sound moves more quickly underwater, and as a result you can hear from a greater distance. Things can be heard from a lot further away and/or are louder than in air. Unfortunately, because of the higher speed, and reflections from the bottom, sound direction is almost impossible to determine by ear.

This is a pretty poorly worded question!!

Advantages of Scuba over what?

One advantage is you dont drown!

Bit more info needed to answer this one!

You can get a PADI certification at any PADI dive shop. The best thing to do is to contact a dive shop in your area and ask about their scuba certifications. If they do not offer PADI certification, they will likely know who in your area does. To find a local PADI dive center, just go to PADI.com and click on Start Diving, which will take you to the shop locater.

There are a couple reasons why you shouldn't hold your breath. First off, holding your breath trying to conserve air could lead to passing out. Slow breathing also helps you relax. Also if you hold your breath at depth and head to the surface, the air in your lungs can expand causing an over expansion of your lungs. A very serious and sometimes life threatening injury.

It simulates weightlesness and using tools in a confined environment. Good training for Nauts.

Weight of the object - weight of fluid it displaces.

If the fluid is water and you are using a pure solid, not hollow, substance this is easily found by subtracting the densities of the two and multiply by its volume.

If the mouse has been certified to go scuba diving and passed a 5 dive on 2 separate days, of course it can dive. Finding a tank that little, might be a problem.

The pressure increase is dependent on density of the water. Pure water at 60F has about 27.78 inches of water column (INWC or INWG) per psi or approximately 0.43197 psi/ft. This is from memory; but it should be close.

Fresh water: 0.43 psi per foot Sea water: 0.44 psi per foot.

So, for each additional 10 feet of depth, figure about 4.3 to 4.4 psi increase in pressure.

You can calculate this yourself by using the fact that fresh water weighs about 62.4 pounds per cubic foot (pcf) and sea water weighs about 64 pcf. Divide those numbers by 144 (the "footprint" of one cubic foot, 12 x 12) and there you go.

It's interesting to note that this pressure is independent of volume or expanse. i.e. the water pressure behind a fresh water dam at 100 feet deep is about 43.3 psi regardless of whether the dam's reservoir is 25 miles long or 10 feet long. Depth and density are the only relevant parameters needed to determine pressure.

Dive pressure, however, would be the water pressure of 43.3 plus the air pressure above the water. So the net pressure on your ears & body would be 43.3 plus 14.7 (one atmosphere)totalling 58 psi,or about 4 atmosphers. That's four times our normal experience. Worthy of careful consideration.

Regarding diving - internal pressure inside ones body EQUALS the atmospheric pressure (14.7 psi). [Otherwise we would be squashed by the athmospere.]

Therefore, the net result is still dependent on depth ONLY - in example given it would be around 2.95 atmospheres.

The pressure of freshwater increases by 1 atm for each 34 ft of depth. The pressure of seawater increases by 1 atm for each 33 ft of depth. If surface pressure is 0.97 atm, simply add that pressure to the pressure of the water.

For seawater, you are exactly 1 atm below the surface... So:

1 atm + 0.97 atm = 1.97 atm

For freshwater, divide 33 by 34 to get the fraction of an atmosphere you're adding to your surface pressure:

33/34 * 1 = 0.97 atm

Then add that number to the surface pressure:

0.97 + 0.97 = 0.94 atm

You could buy your own portable diving compressor, my dive buddy has one, there not silly expensive .

You must get fills from a compressor designed for diving (breathing) as the air is filtered and moisture removed.

During the dive your nose will want to naturally breath in, or take in water so having the nose under the mask helps that NOT to happen. Also if you take on water inside your mask and your nose is not within it will be VERY difficult for you to empty the water.

To empty water from your scuba mask at depth you simply pull it out from your face and breath out through your nose and this causes the water to pour out. How would you do this if your nose is not enclosed within the mask?

And also so that water doesn't go up your nose. And mouth (it doesn't taste good).

Table

PG

BSAC

D

Bühlmann

E

DCIEM

D

NAUI

H

NASE

H

Old Navy

H

New Navy

G

PADI/DSAT RDP

M

SSI

H

Life and death abound beneath the waves. Some find beauty beyond imagination. Others find the detritus of the human experience. It often depends upon just what it is they are looking for. Jacques Cousteau was justifiably astounded by what he'd found.

The emperor penguin.

A pressure foot is used to measure air pressure inside a tank. This means that every square foot of the tank, there is a pound of pressure.

To make the ball go from right to left, kick the bottom right handside of the ball with the inside of your right foot. To make the ball go from left to right, hit the bottom left handside of the ball with the outside of your right foot. And the other way round for your left foot. The harder you hit it, the more it will bend.

The stunt diver

The water pressure is too great. It doubles with every 33 feet of depth. The maximum depth for conventional scuba diving is about 40 m (130 ft), technical divers with specialized gas mixtures may work down to 110 m (350 ft). The depth of the deep sea can be as far down as 4,000 m (14,000 ft)